<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框和外边距</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border: 10px;
            border-style: ridge inset outset groove;
            border-radius: 10px;
            /*元素的内边距会影响元素的宽高*/
            padding-top: 100px;
            padding-left: 100px;
        }
        div>div{
            width: 50%;
            height: 50%;
            background-color: #5bc0de;
        }
    </style>
</head>
<body>
    <div>文本123
        <div></div>
    </div>

</body>
</html>